Within the realms of the Pokémon anime, trainers are nearly always shown to have up to six Pokémon in a mostly consistent team. Ash is normally the exception to this rule, as he sometimes catches up to 10 in a certain region and subsequently rotates his team each battle. However, in the Diamond & Pearl anime, Paul is introduced as Ash's new rival, and his ambitions revolve around having the strongest possible team. This means he ends up owning around twenty different species.
As a character, Paul hates weakness. Consequently, he's often seen discarding Pokémon that exhibit any such weakness. While plenty of Paul's Pokémon are barely featured, there are several that showcase their power and battling prowess, earning them more screen-time as a part of Paul's team.
10 Aggron Was One Of Many Powerhouses On Paul's Team
Despite being a part of Paul's humiliating defeat at the hands of Brandon and his Regi-Pokémon, Lairon wasn't released by its trainer following its poor performance. Instead, it was trained harder and evolved into Aggron in time for Paul's Sinnoh League match with Ash.
The hulking Steel and Rock-type was able to overwhelm Ash's prized Pikachu due to its sheer size and power. This prompted Ash to make a tactical switch out to Infernape to overcome the Aggron. Aggron's aggressive offensive power made it a perfect fit for Paul's team alongside the Electivire and several other formidable battlers, but it was unable to leave much of a lasting impact on the final battle.
9 Paul's Ninjask Was Fast & Dangerous But Fell To Ash's In-Form Infernape
Ninjask was barely showcased in the anime, but it was seen being caught during Paul's flashback. During it, he explained the story about how he met Chimchar, implying that Ninjask had been on his team for a while. However, Paul didn't introduce Ninjask in any of his many battles against Ash until their final bout at the Lily of the Valley Conference.
Ninjask's speed was clear for everyone to see. It flew rings around Ash's Gliscor and forced him to switch in his Infernape earlier than he would have liked. Ninjask was eventually taken down by the Fire-Fighting monkey, but it still did its job in weakening and tiring out two members of Ash's team, even if it didn't register any knockouts itself.
8 Paul Barely Used Gliscor Other Than Against Ash's Gligar
Paul caught Gliscor when Ash and his friends were trying to help the Gliscor and its Gligar followers to escape the city they were trapped in due to strong winds and their inability to glide to safety. Ash was appalled that Paul caught Gliscor, as it left the Gligar in even more peril than they were already in.
When Ash caught a Gligar, Gliscor was pitted against its fellow evolution-line Pokémon, and Paul easily emerged victorious against the inexperienced Gligar. Gliscor was barely used beyond this fight but still proved its battling prowess.
7 Magmortar Became Paul's Main Fire-Type Following Chimchar's Release
In need of a Fire-type following his release of Chimchar, Paul opted to start using a Magmar. It debuted in a flashback that showed it annihilating Veilstone Gym Leader Maylene's Lucario.
Despite the dominant introduction, Magmar struggled against Brandon. It was overwhelmed by his Registeel and was later defeated by his Regirock. However, it evolved into Magmortar in time for his first 6-on-6 bout with Ash, where it was able to inflict a burn upon Pikachu and seriously weaken Ash's Buizel. Magmortar easily defeated Barry's Skarmory in their Sinnoh League match but was left out of the final battle with Ash.
6 Chimchar Never Reached Its True Potential Under Paul
Along with Elekid, Chimchar was one of Paul's original Pokémon back when Ash met him for the first time. However, it eventually fell out of favor with its trainer and was released, leading to Ash adopting it. Chimchar picked up some impressive victories under Paul but was ultimately not enough for him due to its inability to activate its Blaze ability under Paul's command.
Paul deemed it weak because of this. However, he later realized it just needed more care and positive attention to trigger its full potential, with Infernape knocking Paul out of the Lily of the Valley Conference following its successful application of the Blaze ability.
5 Honchkrow Was A Thorn In The Side Of Ash's Grotle
Paul's main Flying-type of choice throughout the Diamond & Pearl anime was Honchkrow after it evolved from its previous form, Murkrow. Honchkrow didn't lose a single official battle for Paul, although it did lose to Ash's Staravia-turned-Staraptor in the Squalville PokéRinger competition.
Other than the PokéRinger defeat, its only other embarrassment was losing in quick fashion to Cynthia's Garchomp as a Murkrow. However, in its superior evolved state, Honchkrow became the bane of Ash's Grotle's existence, notching two victories over Ash's Grass-type. Honchkrow was a huge reason Paul became such a formidable trainer, but after noting its speed was a potential weakness, he left it out of his Sinnoh League team to face Ash and instead opted for the significantly faster Ninjask.
4 Drapion Was By Far Paul's Best Pokémon In The Final Battle Against Ash
Paul's narrow defeat to Ash in their Lily of the Valley Conference match was due to a Pokémon that he'd not previously used against his rival, which was the dual Poison and Dark-type, Drapion. With its deadly Toxic Spikes strategy, Drapion was able to single-handedly weaken most of Ash's team with poison afflictions and eliminate three Pokémon in Torterra, Buizel, and Staraptor.
Paul's strategy obviously revolved around the Ogre Scorpion Pokémon, but the trainer opted to leave out some of his other stronger battlers, leaving Drapion's hard work ultimately unfinished.
3 Ursaring's Brute Strength Became A Valuable Asset To Paul
In Paul's quest to build the strongest possible team, he ended up using a ferocious Ursaring in battle on several occasions. Ursaring struggled twice against Ash's Chimchar, especially when it activated its Blaze ability, but also showcased its own might by sweeping through half of Ash's team during their Lake Acuity fight.
Ash's Pikachu paralyzed Ursaring during this match before its ability of Guts was revealed. Its attack increased significantly when inflicted with a status condition. Ursaring was also formidable at the Sinnoh League in Paul's battle against Barry but was left out of the following match with Ash, due to it not fitting into Paul's strategy.
2 Torterra Was Paul's Longest Serving Pokémon
Torterra was showcased as Paul's starter Pokémon, and as he'd been to several other regions before the events of Diamond & Pearl, it was only natural that it'd have fully evolved into Torterra by this point. Torterra's battling debut in the anime came against the formidable Cynthia and her Garchomp, and despite it falling fairly easily to the Champion's ace, it did manage to bring the Dragon-type to its knees.
Over the course of several battles against Ash, Torterra caused problems for Ash's Pokémon, especially his Gliscor and Staraptor. However, its dominance often led to Pokémon being switched out in order to preserve them, rather than there being easy knockouts. Paul ultimately decided to leave Torterra out of his final team against Ash, but only because it didn't directly fit in with his meticulous planning and strategy.
1 Electivire Grew To Become Paul's Main Pokémon
As Paul's most trusted Pokémon companion throughout the entire anime, Elekid rarely let his trainer down and fully evolved into Electivire via Electabuzz. It ended up reflecting its trainer's attitude and resentment towards Ash and his Pokémon. It sparked a fierce rivalry with Ash's Infernape, which had formerly been mistreated while a part of Paul's team back when it was a Chimchar.
Despite losing the all-important final face-off against Ash's Infernape at the Lily of the Valley Conference, Electivire had already knocked out Gliscor and Pikachu, as well as picking up impressive victories in previous bouts against Ash in its previous two forms.